TABLE 4.

NRMSE, SSIM, and Pearson correlation coefficients of predicted results compared to true ¹¹C-UCB-J images from four networks

	#1: SUVR to SUVR		#2: Ki Ratio to SUVR		#3: SUVR to DVR		#4: Ki Ratio to DVR
	Pred-True	Input-True	Pred-True	Input-True	Pred-True	Input-True	Pred-True	Input-True
AD
NRMSE	16.2% (2.9%)	/	17.8% (3.3%)	/	18.1% (3.3%)	/	20.0% (3.5%)	/
SSIM	0.903 (0.033)	0.866 (0.037)	0.880 (0.032)	0.737 (0.037)	0.890 (0.029)	0.773 (0.033)	0.875 (0.026)	0.795 (0.040)
ρ	0.963 (0.012)	0.932 (0.014)	0.955 (0.014)	0.884 (0.042)	0.937 (0.020)	0.863 (0.024)	0.924 (0.023)	0.799 (0.057)
CN
NRMSE	15.6% (2.6%)	/	16.8% (2.7%)	/	17.4% (2.4%)	/	19.0% (2.5%)	/
SSIM	0.910 (0.030)	0.874 (0.037)	0.890 (0.029)	0.751 (0.021)	0.902 (0.019)	0.781 (0.028)	0.885 (0.024)	0.807 (0.024)
ρ	0.967 (0.011)	0.944 (0.012)	0.961 (0.012)	0.908 (0.022)	0.945 (0.014)	0.883 (0.016)	0.935 (0.016)	0.835 (0.029)
All
NRMSE	16.0% (2.8%)	/	17.4% (3.1%)	/	17.9% (3.0%)	/	19.7% (3.2%)	/
SSIM	0.906 (0.032)	0.869 (0.037)	0.884 (0.031)	0.743 (0.033)	0.895 (0.026)	0.776 (0.032)	0.879 (0.026)	0.799 (0.035)
ρ	0.965 (0.011)	0.937 (0.014)	0.957 (0.013)	0.894 (0.037)	0.940 (0.018)	0.870 (0.023)	0.928 (0.021)	0.813 (0.051)

All the results were displayed by mean (SD)

Abbreviations: AD, Alzheimer’s Disease; All, All the Subjects; CN, Cognitively Normal.